Adjustable cord-hook for door-springs



UNTTTD sTATns PATENT onirica.

WM. BfBARNARD, OF BRISTOL, CONNECTICUT.

ADJUSTABLE CORD-HOOK FOR DOOR-SPRINGS.

Speccation of Letters Patent No. 7,132, dated March 5, 1850.

T0 all fwhom may concern.'

Be it known that I, IVILLIAM B. BARNARD, of Bristol, in the county ofHartford and State of Connecticut, have invented a new and usefulDoor-Spring; and I do hereby declare the following to be a full, clear,and exact description thereof, reference being had to the accompanyingdrawings, which make part of this specification.

The principle of my door spring is to combine with a coiled springacting on a fuse, an adjustable sliding or movable cordhook which shallact to close the door with more or less energy according to therequirements of the season, the state of the wind, or othercircumstances. The door is also, so acted on by my spring alone, as tobe held to its place when closed, with more force than is exerted tocommence closing it when wide open.

The action of my sliding cordfhook is such, that it coperates with theform of the fuse, to diminish or increase the power of the spring toclose the door according as it is placed in one or another position towhich it may be transferred.

In the drawings Figure l is an elevation, Fig. 2 is a top view, and Fig.3, a partial elevation, exhibiting a modification of the adjustablecord-hook support.

In the several figures S is the spring-box containing a coiled springattached at one end to the box and at the other to the axis a; a of thefuse F. The springbox is attached by screws or otherwise to thedoorframe T, and the cord hook I-I is mounted in a dovetailed or othersuitable support M (Figs. l and 2) so that when removed to the greatestdist-ance from the hinged side Z of the door it shall stand as at it,directly opposite to the axis of the fuse when the door is closed; andthen the cord c will be drawn in a direction at right angles to theplane of the door. Its effort to keep the door closed will then, for tworeasons be at a maximum. The irst reason is, that my fuse is so formedthat its taper is more rapid than the rate of diminution of elasticityof the coiled spring by its uncoiling; consequently when the cord iswound up close to the neck n of the fuse the tension on the cord isgreater than when it has been unwound to the part n where the cord willact with a greater leverage to keep the spring wound up, this leverageincreasing faster than the tension of the spring is augmented by thewinding. The second reason is that when the hook H is at h the wholeforce of the spring is exerted to keep the door closed while if itstands at 71 only one component of an oblique force tends to keep thedoor closed and the other tends to draw it from the hinged side towardthe opposite. In sliding the hook H from L toward it, some portion ofthe cord is drawn off from the fuseand the tension of the cord isthereby diminished. Instead of a slot to slide the hook H in as in Fig.l, I shall in some cases, especially for heavy doors make the support Mwith distinct dovetailed steps (L, h, 72,,) as seen in Fig. 2, and shallmake the number of them and the extent of motion of H greater or lessaccording to the total difference of intensity with which I wish thespring to act at diEerent times & seasons.

l/Vhile most door springs when allowed to act at all, are compelled toact, always with equal energy, and in many cases become an annoyanceinstead of a convenience especially in mild weather,hclosi ng the doorwith more violence than is then necessary or desirable, my springs willbe capable by a simple adjustment of the position of the hook to give agentle action barely sufficient to turn the door on its hinges, or by acounter movement to render the spring all thatis desired for promptaction in the severest weather. This benefit of adjusting the positionof the cord hook nearer to or farther from the hinged side of the dooris not confined to fuses of the peculiar form employed by me, but may beapplied in connection' with other door springs.

The attaching of the spring box may be made to the door and of the hookH to the frame T instead of the arrangement of parts exhibited in thedrawings, without altering the principle of the machine.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is- 1. The use of the adjustable cord-hook orattachment for the cord, whereby the tendency of the spring to close thedoor is made to vary at pleasure, as herein set forth.

2. I also claim in combination with a of position of the hook alone, inthe manner and for the purposes herein set forth.

WM. B. BARNARD.

Witnesses:

J. A. WELLS, ANNA K. WALL.

